# C# solution for Leetcode question: Convert BST to Greater Tree (difficulty : easy)

Source:

**Convert BST to Greater Tree**

*Given a Binary Search Tree (BST), convert it to a Greater Tree such that every key of the original BST is changed to…*leetcode.com

Given a Binary Search Tree (BST), convert it to a Greater Tree such that every key of the original BST is changed to the original key plus sum of all keys greater than the original key in BST.

**Example:**

Input:The root of a Binary Search Tree like this:

5

/ \

2 13

Output:The root of a Greater Tree like this:

18

/ \

20 13

My C# solution is here: